In designing advertising campaigns to sell magazines, it is important to know how much time each of a number of demographic groups spends reading magazines. In a preliminary study, 40 people were randomly selected. Each was asked how much time per week he or she spends reading magazines; additionally, each was categorized by gender and by income level (high or low). The data are stored in the following way: column 1 = Time spent reading magazines per week in minutes for all respondents; column 2 = Gender (1 = Male, 2 = Female); column 3 = Income level (1 = Low, 2 = High).

a. Is there sufficient evidence at the 10% significance level to conclude that men and women differ in the amount of time spent reading magazines?

b. Is there sufficient evidence at the 10% significance level to conclude that high-income individuals devote more time to reading magazines than low-income people?